These families are difficult to sort out because the same names were in several families. RootsWeb Family Trees:

Johannes / John {John Georg?} ELLWEIN (11 July 1845, Crimea - _ ) m. 1867, Crimea, Maria WALZ (30 Apr. 1847, Crimea - 14 Dec. 1912, Mannhaven, Mercer Co., ND) d/o Johannes WALZ & Barbara MAIER. Maria & John ELLWEIN had in Crimea:

Rachel (15 Dec. 1868 - 1869)
Jacobina (30 Sep. 1870 - 1 Oct. 1942, SD) m. 18 Feb. 1887, Christian WALZ.
Susanne/ Susanna (29 Sep. 1872 -1945, ND) m. John BAZLER.
Maria (8 Dec. 1874 - 1876)
Elizabeth (8 Mar. 1877 - 14 Apr. 1887, SD)
Christina (12 Feb. 1879 - 1886)
Wilhelm (30 Sep. 1881 - 9 Jan. 1922, Burleigh Co., ND) m. 5 Je. 1904, Mannhaven, Mercer, ND, Emilie KÃ…MPF, b. 25 Mar. 1884, Klostitz, Akkerman, Bessarabia.
Johannes (1 Feb. 1884, Neudorf, Crimea - 18 Sep. 1959, Burleigh Co., ND) m. 12 Feb. 1907, Mercer Co., ND, Katharina SAILER (of Peter of Adam).

ELLWEIN burials in the Haar Cem., Freeman, Hutchinson Co., SD:
John, 10 Feb. 1912, 66 [Age must have been overstated because he is probably John, b. ca. 1847/8, husband of Elizabeth.]
Elizabeth, 24 Je. 1904, aged 54
Beate, 29 Mar. 1918, 33
Johannes, 4 Apr. 1888, 14 {s/o John & Eliz., 2 in '76, 6 in '80}
Edward, 27 Dec. 1886, 2
Hugo, 16 Dec. 1905, one day
Emma, 24 Nov. 1896, 21 days.

Freeman Cem., Freeman, Hutchinson Co., SD, ELLWEIN:

Adela, 1911, 13
Helene Rosa, 1925, 1
Hellmut Edwin, 1901
Jacobina, 74, & Mathaus, 78, no dates.

Castle Garden, NY, online immigration records show that Matheus, 52, & Jacobina, 48, arr. 9 Oct. 1878 on the Frisia. These arrived 14 June 1876 on the Hammonia, ELWEIN, Johs., 28; Elisabeth, 25; Franz, 9; Jacobine, 8; Jacob, 6; Johs., 2; Alexander, 5 mos.

On the Trave from Germany, arr. 6 Nov. 1886, ELWEIN, Georg, 41; Marie, 39; Jacobine, 16; Susanne, 14; Elisabeth, 7; Wilhelm, 5; & Johann, 2 {perhaps the father was John Georg}.

These arrived 2 Nov. 1893 on the Spree: ELLWEIN, Mathias, 41; Marg. 36; Maria, 12; Lydia, 8; Franz, 2; & Emilie, 5 mo. (female).

FamilySearch database of the 1880 Census, Hutchinson Co., SD:

ELLWEIN, Johanes, 32; Elisabeth, 29; Jacobine, 12; Jacob, 9; Johanes, 6; Alexander 4; Andreas, 3; David, 11 mos. Father Matthaeus, 54; mother Jacobine, 49. All b. in Russia except Andreas & David. Heinrich, 26, & family were also on the census in Twp. 98, & Christian, 29, & family were in Twp. 97.

ELLWEIN land patents, Hutchinson County, SD:

Christian, 97 - 56, Section 5, NE & NW.
Heinrich, 98 - 56, 23 SW
Johannes, 98 - 56, 30 SW, 31 NW.

I'll post more later.